NO. 1160. LEECHES OF THE U. S. NATIONAL MUSEUM— MOORE. 555 



CYSTOBRANCHUS Diesing. 

 II. CYSTOBRANCHUS species? 



No. 1594, U.S.X.M. Albatross station 2737. One specimen. 



PISCICOLA Blainville. 



The genus Piscicola as here used is composite and requires subdivi- 

 sion, but no adequate system has yet been proposed. 



12. PISCICOLA GEOMETRA (Linnaeus) Blainville. 



No, 237, U.S.N. M. Wasliiugton, District of Columbia, February 3, 

 1883. On German car]) (probably introduced with these fish). Three 

 specimens. 



13. PISCICOLA SEXOCULATA. 

 riatybdella sexoculata Malm. 



No. 4850, U.S.N.M. St. Pauls Island, Bering Sea, June, 1890; Wil- 

 liam Palmer, from Sculpin. Five specimens. 



14. PISCICOLA SCORPII. 



Jlirudo acorpii FabrigiL's. 

 I'latijhdeUa ncorpii Mal.m. 

 rUcicola multistriata Gkcbk. 



No. 5029, U.S.N.M. St. Pauls Island, Bering Sea; William Palmer, 

 June, 1890, from Sculpin. Six specimens. 



No. 3944, U.S.N.M. From Sculpin. One specimen. 



15. PISCICOLA ZEBRA, new species. 



This Species has tlie slender, somewhat depressed, nearly linear form 

 of P. geomctra, but the posterior sucker is nearly circular, and much less 

 excentrically fixed, the anterior is smaller, the annulation shows some 

 peculiarities, and tlie color is very different. In these specimens no 

 respiratory vesicles are vi.sible. 



The anterior body region contains twenty-one primary annuli, of which 

 the first five are undivided, six to fifteen are distinctly broader and biau- 

 nulate, and the secondary rings often again biannulate, making four 

 minor or tertiary rings to each primary annulus. Then begins the cli- 

 tellar region with annuli sixteen to eighteen narrower and less distinctly 

 biannulate. The male pore is in the posterior part of eighteen, and is 

 bounded behind by a narrow fold. In contracted specimens this imre 

 appears to be between eighteen and nineteen, owing to the supjiression 

 of the fold. Nineteen and twenty are similar, with the female pore 

 behind tlie latter. Twenty-one and the following annuli are again 

 distinctly and doubly biannulate. The po.sterior region begins with 

 twenty-two. 



Tlie typical somites of the posterior region have fourteen annuli of 

 the third and fourth ordecs; the first and third primary annuli have 



